tailieunhanh - Practical TCP/IP and Ethernet Networking- P50

Practical TCP/IP and Ethernet Networking- P50: The transmitter encodes the information into a suitable form to be transmitted over the communications channel. The communications channel moves this signal as electromagnetic energy from the source to one or more destination receivers. The channel may convert this energy from one form to another, such as electrical to optical signals, whilst maintaining the integrity of the information so the recipient can understand the message sent by the transmitter | Security considerations 227 CERT The CERT Computer Emergency Response Team co-ordination center is based at the Carnegie Mellon Software Engineering Institute and offers a security advisory service on the Internet. Their services include CERT advisories Incident notes Vulnerability notes Security improvement modules The latter include topics such as Detecting signs of intrusions Security for public web sites Security for information technology service contracts Securing desktop stations Preparing to detect signs of intrusion Responding to intrusions Securing network services These modules can be downloaded from the Internet in PDF or PostScript versions and are written for system and network administrators within an organization. These are the people whose day-to-day activities include installation configuration and maintenance of the computers and networks. Once again a particular case in point is the CERT CC dated March 27 1999 which deals with the Melissa virus which was first reported at approximately 2 00 pm GMT-5 on Friday 26 March 1999. This example indicates the swiftness with which organizations such as CERT react to threats. CSI CSI The Computer Security Institute is a membership organization specifically dedicated to serving and training the information computer and network security professionals. CSI sponsors two conferences and exhibitions each year NetSec in June and the CSI Annual in November. CSI also hosts seminars on encryption intrusion management firewalls and awareness. They also publish surveys and reports on topics such as computer crime and information security program assessment. The public-key infrastructure PKI Introduction to cryptography The concept of securing messages through cryptography has a long history. Indeed Julius Caesar is credited with creating one of the earliest cryptographic systems to send military messages to his generals. Throughout history however there has been one .